What they found wasn't the catch they were looking for — instead of dolphin, they pulled Morris and McGovern out of the water, dehydrated and shivering from their journey. After seeing the fishing boat, McGovern hoisted his shirt above his head and held onto Morris, who was becoming very weak.

"The [woman] couldn't even walk," one of the fishermen, Steve Couch, said. "Her legs were like sticks. They couldn't even bend."

McGovern, 49, of Key Largo, told the fishermen that Morris, 51, was visiting him from Texas.

The couple were in Key Largo on the back of their 30-foot Island Hopper when they fell into the water about 6 p.m. Friday.

Officials haven't said why the couple, who weren't wearing life jackets, fell from the back of the boat. The watercraft was in high gear and drifted away from them, the Coast Guard said.

"I don't know what they were doing when they fell over, but they must've been having a good time," Couch said.

In addition to Couch, the fishermen were two off-duty Broward sheriff's detectives, Adam White and Josh Webb, and firefighter/paramedic Keith Silvas. Couch is White's father-in-law.

The fishermen said they hadn't been out on the boat for more than 20 minutes when they saw the two stranded in the ocean.

They said they saw the birds and figured fish were nearby, and had it not been for that, they might've never gone over to the spot where they found McGovern and Morris.

"It was a strange thing," Couch said. "My first thought was, 'How did you get out here?'"

When the men pulled the swimmers out of the water, they said the couple were pruned from head to toe and dehydrated.

Morris was in such bad shape, she wasn't even swimming when their boat pulled up, Silvas said. Her legs were so cramped and her body so weak, the men had to pull her into the boat and Webb gave her his long-sleeved navy blue shirt.

The group pressed the couple about their dramatic 13-hour swim while giving them food and water.

How did they stay up at night?

How did they get so far?

Did they know where they were?

They were skeptical at first about the couple and how they got to be in the open water.

With past stories of piracy and of boaters being tricked, they were wary. But after seeing the couple's condition and hearing their story, they were put more at ease.

Webb said the couple were quiet about their journey, but shared some details about their survival.

"That's a good float — from Key Largo to here," Webb said. "I couldn't believe it. She was telling us they were trying to fight to stay close to the shore. She was hanging onto his feet to stay together at night."

The couple used light from the coastline as their guide, Morris told them. McGovern would nod off to sleep in the night while floating, and she would shake him awake, Morris told the fishermen.

When the Coast Guard arrived, it verified the two were U.S. citizens and gave them medical aid. The couple's missing boat also turned up Saturday afternoon. It appeared on the beach near the Ocean Manor Beach Resort in Fort Lauderdale, the Coast Guard said.

The couple could not be reached for comment.

Silvas said he has been trained specifically to care for people left out at sea or who are in need of a water rescue. He said he didn't know how much longer the couple could've made it floating in open water.

Based on where the couple were rescued, the fishermen predicted the current would've taken them much farther north in a few hours.

"They're some lucky people," he said. "Thank God the seas were calm. If we wouldn't have found them, they'd be somewhere in north Florida if they were able to survive."

After the Coast Guard took the couple to shore, friends picked them up, the Coast Guard said.

The foursome, however, continued their day at sea. They docked their boat in Dania Beach on Saturday afternoon, unloaded their coolers full of fish and regaled friends at the marina about their unexpected day at sea.

"It was interesting for sure — I'll never forget it. I bet they'll never forget it," Webb said. "That's a lot of will to survive."